I.1.6 Triple Integrals

Calculate body weight \ (v \) with density \ (\ rho \), limited by these planes: \ [\ begin {array} {l} v: x = 0, \ quad y = 0, \ quad X+y+z = 1; \\ \ rho (x, y, z) = \ frac {1} {(1+x+y+z)^{3}}. \ end {Array} \]